Re: [PATCH v12 7/7] kasan: don't run tests in async mode

From: Catalin Marinas <catalin.marinas@arm.com>
To: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>,
	Marco Elver <elver@google.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Andrey Konovalov <andreyknvl@google.com>,
	Evgenii Stepanov <eugenis@google.com>,
	linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
	Alexander Potapenko <glider@google.com>,
	linux-arm-kernel@lists.infradead.org,
	Andrey Ryabinin <aryabinin@virtuozzo.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Will Deacon <will@kernel.org>, Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [PATCH v12 7/7] kasan: don't run tests in async mode
Date: Tue, 9 Feb 2021 12:02:42 +0000	[thread overview]
Message-ID: <20210209120241.GF1435@arm.com> (raw)
In-Reply-To: <20210208165617.9977-8-vincenzo.frascino@arm.com>

On Mon, Feb 08, 2021 at 04:56:17PM +0000, Vincenzo Frascino wrote:
> From: Andrey Konovalov <andreyknvl@google.com>
> 
> Asynchronous KASAN mode doesn't guarantee that a tag fault will be
> detected immediately and causes tests to fail. Forbid running them
> in asynchronous mode.
> 
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>

That's missing your SoB.

> diff --git a/lib/test_kasan.c b/lib/test_kasan.c
> index 7285dcf9fcc1..f82d9630cae1 100644
> --- a/lib/test_kasan.c
> +++ b/lib/test_kasan.c
> @@ -51,6 +51,10 @@ static int kasan_test_init(struct kunit *test)
>  		kunit_err(test, "can't run KASAN tests with KASAN disabled");
>  		return -1;
>  	}
> +	if (kasan_flag_async) {
> +		kunit_err(test, "can't run KASAN tests in async mode");
> +		return -1;
> +	}
>  
>  	multishot = kasan_save_enable_multi_shot();
>  	hw_set_tagging_report_once(false);

I think we can still run the kasan tests in async mode if we check the
TFSR_EL1 at the end of each test by calling mte_check_tfsr_exit().

-- 
Catalin

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